1. Field of the Invention
The present invention relates to a disk changer apparatus capable of storing a plurality of disks, such as compact disks (CDs) and digital versatile disks (DVDs), in a case and selecting one of the disks to drive it.
2. Description of the Related Art
Disk changer apparatuses are used as, for example, in-car disk apparatuses, in which a plurality of disks are stacked in the thickness direction and are stored in a case. When a user selects one of the disks, the selected disk is rotated to read and/or record information.
Such a disk changer apparatus includes a plurality of disk supporters for holding the disks, a disk selection mechanism for moving one of the disk supporters to a selected position, a rotation base which has a turntable and a head and which is rotatable, in a case, about a rear end thereof as a fulcrum, a driving mechanism for rotating the rotation base between a driving position and a standby position, and a disk transport mechanism for transporting a disk inserted into a disk insertion port on the case to the disk supporter and ejecting the disk from the disk supporter to the disk insertion port. Here, the driving position is a position where the center of a disk held by a disk supporter located at the selected position or a disk pulled out from the disk supporter is aligned with the center of the turntable, and the standby position is a position where the rotation base does not overlap the disk supported by the disk supporter.
To properly clamp a selected disk on the turntable of the rotation base and reliably carry out playback and recording of information in the disk by the head, the rotation base needs to be precisely positioned at the driving position. Also, a vibration-proof structure is required to prevent vibration caused by, for example, a moving vehicle from being transmitted to the rotation base via the case.
To precisely position the rotation base, a disk apparatus such as is disclosed, for example, in Japanese Unexamined Patent Application Publication No. 10-003729 has been known. The disk apparatus disclosed in Japanese Unexamined Patent Application Publication No. 10-003729 includes a rotation arm (rotation base) which has a turntable and a head and which rotates about a rear end thereof as a fulcrum (a first fulcrum). The disk apparatus further includes a link which rotates about a rear end thereof as a fulcrum (a second fulcrum). The top end of the link is connected to the rotation base by a pin (a third fulcrum). When the rotation arm moves from the standby position to the driving position, the link rotates while following the rotation arm. When the rotation arm reaches the driving position, the rotation arm is properly positioned by the first, second, and third fulcrums. Furthermore, two positioning tabs are provided to a disk holder in a disk holding unit. The two positioning tabs pinch the top end of the rotation arm when a disk held by the disk holder is mounted on the turntable so as to determine the position of the rotation arm.
On the other hand, Japanese Unexamined Patent Application Publication No. 11-162079, for example, discloses a disk apparatus having a vibration-proof structure for the rotation base. In the disk apparatus disclosed in Japanese Unexamined Patent Application Publication No. 11-162079, a swing arm which rotates between a driving position and a standby position and a drive arm which also rotates between the driving position and the standby position are coaxially aligned and are rotatably mounted on a support part resiliently supported by two vibration dampers provided in a case. A turntable and a head are mounted on this drive arm. Another vibration damper is attached to an end of the swing arm. The drive arm is supported by the swing arm via the vibration damper. When a disk is clamped on the turntable, the drive arm is resiliently supported by the three vibration dampers, namely, the two dampers for resiliently supporting the support part and the vibration damper attached to the swing arm.
In the disk apparatus disclosed in Japanese Unexamined Patent Application Publication No. 10-003729, the position of the rotation base rotated to the driving position is determined by three points using the link. At the same time, two positioning tabs provided to a disk supporter limit the movement of the rotation base in the vertical direction (in the thickness direction of a disk).
However, in the disk apparatus disclosed in Japanese Unexamined Patent Application Publication No. 10-003729, the link is always connected to the rotation base and rotates with the rotation base. Accordingly, the structure is complicated. Also, to precisely position the rotation base at the driving position, the positions of three fulcrums need to be precisely determined. This requires high precision machining and assembly, thus increasing the manufacturing cost.
Additionally, two positioning tabs formed on the disk supporter limit the position of the rotation base in the vertical direction. These positioning tabs are required to be provided to all of the disk supporters in the case. This further increases the cost.
In the disk apparatus disclosed in Japanese Unexamined Patent Application Publication No. 11-162079, three vibration dampers are disposed between a case and a rotation base to prevent vibrations from being transmitted via the case.
However, when the rotation base rotates to the driving position, positioning of the top end of the rotation base, on which a turntable is mounted, is not precisely determined. Therefore, when a disk clamped on the turntable is driven to rotate, vibration tends to occur at the end of the rotation base.
Furthermore, in the disk apparatus disclosed in Japanese Unexamined Patent Application Publication No. 11-162079, the damper arranged in the vicinity of the turntable is not secured to the case, but is mounted to the end of the swing arm, which rotates about the base end thereof as a fulcrum on the case. Accordingly, if vibration is transmitted to the case, the swing arm also receives the vibration. This vibration tends to be transmitted to the rotation base having the turntable and the head.